Manuscript Summary: This is a copy, significant in terms of textual history, of books VI to X of the Expositio in Apocalypsin by Ambrosius Autpertus († 784), presbyter and abbot, originally from southern Gaul, but active in the southern Italian monastery of San Vincenzo al Volturno. The copy, transcribed by a variety of hands from a lost 9th century Reichenau manuscript, was made at the monastery of St. Gall. It contains multiple glosses by the hand of the monk Ekkehard IV. (smu)